Insider Trader is a column about professions by Basil "Euripides" Berntsen, who also writes Gold Capped about how to make money using the auction house. Email Basil your questions.
The state of all the professions in Cataclysm is still in a bit of flux, but at least most of the recipes have been added to the beta now. Like most professions, tailoring post-Cataclysm is going to look very similar to the way it looks now. Sure, all the numbers are higher, but the structure of the profession is basically the same.
One of the key differences, however, is that while tailoring has historically required mostly cloth and vendor trash for recipes, it is now a serious consumer of "volatile" elementals. Look through the recipes you start doing in Wrath of the Lich King and you'll see mostly bolts of Frostweave. You still need the new type of cloth (Bolt of Embersilk Cloth); however, virtually every single recipe you'll want to train on, as well as most of the actually useful (and valuable) recipes, are going to involve Volatile Water, Volatile Fire, Volatile Life, and Volatile Air. This is also true of the other gear-crafting professions, leatherworking and blacksmithing; however, tailoring had one thing going for it that other professions didn't: Unraveling.